Feed hechanism for engine-cylinder-reboring machines



MECHANISM FOR. ENGINE CYLINDER REBOFHNG NEAm-HNES,

APPLICATION FILED JULY 8.19m.

FEED

P:v tamed Nov. M; 191.

' UNITED STATES PATENT curios- ROBERT E. ROS EBERRY, 013 DETROIT, MICHIGAN, ASSIGNOR TO THE UNIVERSAL TOOL COMPANY, INC., OF DETROIT, MICHIGAN.

FEED MECHANISM FOR ENGINE-CYLlINDER-REBORING MACHINES.

Specification of Letters Patent.

Patented Nov. 1.1., 1919.

Originalapplication filed October 23, 1917, Serial No. 198,160. Divided and this application filed July 8,

1918. Serial No. 243,839.

To all whom it may concern:

Be it known that I, ROBERT E. RosEBEnnY, citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Feed Mechanism for Engine-Cylinder-Reboring Machines, of which the following is a specification.

This invention relates to an improved feed mechanism for portable machines for reboring engine cylinders, being a division of my pending application filed October23, 1917, Serial Number 198,160.

The-invention has as itsprimary object to provide a change speed gearing which 4 may be operated 1n connection with the disclosed feed screw employed in such manner that while the cutter mechanism which is con nected directly to the feed screw, is both rotated and advanced through the cylinder by movement of the screw, the rate of advance of the cutters may be varied at will, as for instance, from a rate of six turns to the inch to a rate of say thirty-four turns to the inch.

The invention has as a further object to provide a construction permitting the use of coarse screw threads in the feed mechanism so that there will be less wear and strain upon the individual thread and all likelihood of crossing of the threads avoided.

And the invention has as a further object to provide a feed mechanism wherein the feed screw may be advanced slowly for effecting the reboring operation while, at the same time, the said screw.may be rapidly withdrawn or retracted after the boring operation is completed.

Other and incidental objects willappear as the description proceeds. ings, wherein I have illustrated the preferred embodiment of the invention, and wherein similar reference characters designate corresponding parts throughout the several views:

Figure l is a vertical sectional view showing my improved feed mechanism in connection with a rcborlng machine of the type In my pending application referrcd to,

In the draw- Fig. 2'is a horizontal sectional view taken on the line 2-2 of Fig. 1, i

Fig. 3 is a fragmentary sectional view taken centrally of the jack shaft forming a part of the variable speed gearing of the feed mechanism, and

Fig. 4 is a fragmentary perspective view of the jack shaft and key'cooperating therewith.

Referring now more particularly to the drawings, I have shown my improved feed mechanism in connection with a reboring machine of the type illustrated in my pending application previously identified. Briefly stated, this reboring machine includes a body 10 having oppositely directed base flanges 11, braced by webs 12. Formed in the ase flanges are slots 13 adapted to receive cap screws for connecting the body with the cylinder block to aline axially with a cylinder to be rebored. At its upper end thebody is provided with an annular seat receiving a capplate 14 lying flush with the upper end of the body and connected therewith by a plurality of cap screws 15 threaded into suitable bosses l6 projecting inwardly from the wall of the body. .Up-

alining axially with the sleeve 17. Jourv naled throughthe sleeves 17 and 19 is a feed screw 20 provided, throughout the major portion of its length with a relativelycoarse square thread. At its upper end the feed screw is squared forreceiving any approved tool for rotating the screw, and connected to the lower end of the screw is a cylindrical cutter head -21 upon which is mounted a plurality of adjustable radially disposed cutters or blades 22. The head 2i is, of course, adapted to fit within the cylinder being bored so that rotation of the feed screw 20 will act to revolve the head within the cylinder for effecting the cutting operation. An expansible pilot ring 23 is adapted to fit upon the lower end of the cutter head for guiding the-head through feed screw and rests upon the partition wall 18. A washer 26 fits loosely about the I feed screw to seat upon the combined nut and gear and resting upon this washer is a spur gear 27 of-slightly less diameter than 15 the gear 25. The feed screw throughout its entire length is formed in one side with a longitudinal channel or keyway 28 which, if desired, need be of no greater depth than the depth of the thread of the said screw, and the spur gear 27 is. formed with anintegral projection or key 29 fitting loosely 111 this .keyway; It will, therefore, e apparent that while the feed screw is free for move ment throulgh the gear 27 such gear will always be driven when the feed screw is rotated. A A shaft 30 has one end journaled in a bearing 31 formed in the partition wall 18 and projects through the cap plate 14, to be journaled in a. bushing 32 shrunk into the cap plate and securely, held against movement therein. 'This shaft carries a spur pinion 33 which is preferably formed integral with the shaft and also carries a. loose pinion 34, these pinions meshin with the gears 25 and 27 respectively. The pinion 341sformed with a key seat 35 and-the bushing 32- with a key seat 36 adapted in one position of the'pinion 34 to aline with and form a continuation of the seat 35. It should be noted that this latter key seat, however, does not open through the top..of the bushing so that a stop shoulder is'prov'ided, The shaft 30 is formed witha 'keyway 37 extendthe level ofthe lower end of the in -fro ke sdi 35 through the outer end of the --jshaft an'd slidably mounted in this 'keyway is a key slide 38 provided at its lower end with a key proper or. extension '39 operating. in -the key seats 35 and 36 and capable of being. disposed wholly in either one or the other of these seats. llhe upper end .of the slide, even when it is in itslowest position, projects above the shaft 30 and through a knob 40 which surrounds the extendcdendof the shaft, being secured to move withthe knob, as indicated at 41. 'Obviously, withthis arrangement, by raising and lowering-v the knob the key 39'may be moved into the the knob 40 is formed with a diametric opening 42' leadin into the keyway, and disposed within t is openin is a detent forming ball 43 which .is-h d against the rear face of the. key slide by a spring 44. The inner face of the slide 38 is formed at a suitable point with a seat 45 receiving this detent so that the knob and this key slide may be frictionally held in elevated position with the key 39 in the key seat 36, at such times as this position of the parts is desired. A second seat 46 is formed in the key slide to receive the detent 43 for frictionally holding the key 39 in lowered position within the key seat 35 of the gear 34.

As will now be clear, by depressing the knob 40 to occupy the position shown in Fig. l, and thus locking the pinion 34 to the shaft 30, the feed screw 20 may be turned in a' clockwise direction for rotating the cutter head 21 when the said feed screw will be fed axially through the body for advancing the cutter head. through the cylinde-r being rebored. After the cutter head has moved the entire length of the cylinder, the knob 40 is then pulled to extended position to free the pinion 34 from the shaft 30, when the feed screw is counter-rotated to free the cutter mechanism from the cylinder, after which the machinev may be removed. With the pinion 34 locked to the shaft 30 by the engagement of the key extension 39 in the key seat 35, a slow feeding of the cutter mechanism is obtained, due to the fact that 'turningof the feed screw dri vesthe gear 27 which, owing to the presence of the keyway and key connection between the pinion 34 and shaft 30, in turn drives the said shaft. and consequently the combined gear and feed nut 25 from the pinion '33 in the same direction as the feed screw but at a slightly slower rate of speed. Ob vionsly, with the feed nut turning in the same direction as the feed screw but ,at a slower rate of speed, the advance of the feed screw through the nut will be relatively slow. On the other hand, when the feed nut is locked stationary by the engagement of the key extension 39 in the key seat 36 the rate of travel of thefeedj screw will be accelerated notwithstanding that the rate of rotation of the screw remains constant. I

have found that the most convenient and ,efli'cient feed mechanism is one in which direct movement of the feed screw through its nut, when the nut is stationary, is at the rate of one inch to every six revolutions jof the screw and in which the nut when driven moves at such speed relative to. the .feed screw as to cause advance of the feed .screw through a distance of one inch for thirty-four revolutions of the feed screw.

.seat 36 or the seat 35 as the case ma be.

mechanism may be fed slowly andj odnsd The shaft 30 at that portion inclosed within quently with less effort, while the actualresboring is being done, and may, nevertheless, be rapidly withdrawn after the? ring operatwn 'is completed, a-rnere shift of the knob being allthtt lisnecessary to acmechanism carried by the feed screw and rocom'plish these results. Preferably, the easing is formed with a radial groove or mark and the sleeve portion of the knob with a groove or mark which when brought into alinement with that of the case will indicate that the key receiving seat of the bushing 32 and the key receiving seat of the pinion are in alinement with each other so that the key may 'be shifted. This is possible due to the fact that the knob turns with the shaft 30. By the employment of this cl'iange speed gear as part of the driving mechanism for the cutter, it is possible to not only have the desired slow feed during a cti to; operation of the cutter and rapid retraction of the cutter after the boring operation completed, but it is also possible to employ a feed screw having a relatively warse square thread which permits the pro vision of the spaced. bearing sleeves 17 and '19 for the feed-screw. This is an important feature as these bearing sleeves prevent any undesired movement of the feed screw suc aS might result in the formation of ah untrue bore in the cylinder.

Having thus descri is claimed as new is;

1. In an engine cylinder reboringpmachine, a supporting body, a feed screw ournaled in the body, a feed nut supported by the body and engaging the screw, a cutter tatable thereby, and -means for selectively coupling the nut with the screw or holding said nut stationary with respect thereto for varyin the rate at which the feed screw will be fed through the feed nut while the rate of rotation of the feed screw remains constant.

2. In an engine cylinder reboring machine, a supporting body, a feed screw journaled in the body, a feed nut supported by the body and having engagement. with the screw, cutter mechanism rotatable from the feed screw, and means for selectively holding the feed nut against turning movement during turning of the feed screw to accomplish a rapid movement of the screw through the nut or for causing turning of the nut by the screw in the same direction as the feed screw but at a lower rate 'of'speed than the speed of the feed screw through the nut.

In an engine cylinder reboring machine, a supporting body, a feed screw journaled in the body and formed with a longitndinal-keyway, gears-mounted upon the feed screw and supported by the body, one of the gears having akey engaging in the keyway and the other being formed with a thread engaging the thread of the feed screw whereby it provides a feed nut, a shaft journaledjn the body, a pinion carried by the shaft and meshing with that bed the invention, what feed screw to cause a slow feeding of the b gear having threaded engagement withthe feed screw, a pinion carried by the shaft and meshing with the gear having keyed engagement with the feed screw, means for selectively connecting and disconnecting the latter pinion and shaft, and. cutter mechanism rotatable from the feed screw.

4.- In an engine cylinder reboring ma chine, a supporting body, a feed screw journaled in the body and formed with a longitudinal keyway, gears mounted upon the feed screw and supported by the body, one of the gears having a key engaging in the .keyway and the other being formed with a thread engaging the thread of the feed screw whereby it provides a feed nut, a shaft journaled in the body, a pinion carried by the shaft and fastened therewith meshing with that gear having threaded engagement with the feed screw,a pinion carried by the shaft and meshing with the gear.

having keyed engagement with the feed.

screw, and means for selectively connecting and disconnecting the latter pinion and shaft, said means includinga key receiving seat formed in the pinion, a key receiving seat formed in the supporting-body, a key element slidable in a keyway formed in the shaft and having a key: proper movable into either seat, and means supported by the shaft and engaging the key proper for reciprocating it. v

5. In an engine cylinder reboring machine, a hollow supporting body open at its ends, a cap plate closing one end of the body and formed centrally with a bearing sleeve,

a partition extending across the body in spaced relation to the cap plate and formed with a bearing sleeve alined with said first mentioned sleeve, a feed screw journaled in said sleeves, a cutter mechanism carried by the lower end of the feed screw and rotatable therefrom, ,and means inclosed between the cap plate and partition for selectively varying the rate of advance of the feed screw for a constant rate of rotation thereof. 6. In an engine cylinder reboring machine, a supporting body, a feed screw loose with respect to the body and rotatable thereon, cutter mechanism carried by the screw and rotatable therefrom for effecting the cutting operation, and means-normally coupled with the feed screw for advancing the screw upon its rotation and operable to be locked stationary with respect to the screw for changing therate of such advance for a constant rate of rotation of the screw. 7. In an engine cylinder reb'oring 1nachine, a supporting body, a feed screw loose with respect to the body and rotatable thereon, cutter mechanism carried by the feed screw and revoluble therefrom for elfecting the cutting operation, a feed not engaging the screw and adapted to advence the screw upon the rotation thereofyafid-means for r0 toting the said. nut from the screw and in the direction of r0tation of the screw or for holding the nut stationary.

8. In a'eylinderreboring machine, the combination with a'supporting body pro:

the screw and rote-table thereby, of ineans disposed between the bearings and normallycoupled with the screw for advancing the screw upon its rotation, and means for locking the first means stationary with respect 15 to the screw for changing'the rate of such advance for a' constant rate of rotation of the screw.

-. In testimony whereof z'tffix my signature. I

ROBERT E. ROSEBERRY. 1.5.] 

